Spawnable Mods on Scepters/Rods

What can spawn on a 1 handed wand that already has +15 energy/-1 degen?

Also are there any places to acquire perfects of these weapons? i browsed the collectors on wiki and found nothing with a +15/-1 mod that wasnt for the other hand

Nothing else.

i think all wands can have mods, so you would be able to get anything but skill+1 and armor.
exampes of second mods
10% recharge, +5 enchanted, 20% fast cast

You mean something like this..?

Yes they can, as seen in the pic above. You can also get them crafted in factions and in prophecies. In prophecies they are scattered around. But there is a colletor in Nebo Terrace outstide of town there that has a blood version. In Cantha there are weapons crafters in town that have one for every class. I believe it is in Maatu?

Yes, all 15/-1 versions of one handed wands are available in Maatu, and each has a 20% chance of halving the skill recharge on that attribute's spells.